NOTE: This disposition is nonprecedential.

 

United States Court of Appeals 

for the Federal Circuit ______________________ 

ERIC LEMOINE, TTC PERFORMANCE 

PRODUCTS, INC., DBA BLACK ACES TACTICAL,

Plaintiffs-Appellants

v.

MOSSBERG CORPORATION, O.F. MOSSBERG & 

SONS, INC.,

Defendants-Appellees

______________________ 

2020-2140

______________________ 

Appeal from the United States District Court for the 

District of Connecticut in No. 3:18-cv-01270-KAD, Judge 

Kari A. Dooley.

______________________ 

Decided: September 15, 2021

______________________ 

LOU GIGLIOTTI, JR., Louis R. Gigliotti, PA, Hollywood, 

FL, for plaintiffs-appellants.

 JASON STEWART JACKSON, Kutak Rock LLP, Denver, 

CO, for defendants-appellees. Also represented by CHAD T.

NITTA. 

 ______________________ 

Case: 20-2140 Document: 26 Page: 1 Filed: 09/15/2021
2 LEMOINE v. MOSSBERG CORPORATION

Before LOURIE, O’MALLEY, and REYNA, Circuit Judges.

REYNA, Circuit Judge.

Appellants, Eric Lemoine and TTC Performance Products, Inc. d/b/a Black Aces Tactical, appeal from a stipulated judgment of noninfringement following a claim 

construction order by the United States District Court for 

the District of Connecticut. Because we discern no error in 

the district court's claim construction, we affirm. 

BACKGROUND

U.S. Patent 8,756,846 (the ’846 Patent) discloses a 

“shotgun magazine receiver assembly” that “relates generally to shotguns and, more particularly to a retrofit magazine receiver for use with a conventional shotgun” that 

“allow[s] a user to rapidly fire and reload ammunition via 

a removable ‘box’ style magazine.” ’846 Patent col. 1 

ll. 6–8, 34–35.

The only disputes at issue on appeal relate to the preamble of claim 1, which is reproduced below: 

A shotgun magazine receiver assembly for converting a conventional shotgun having a trigger assembly and barrel into a magazine loaded shotgun, said 

receiver assembly comprising:

Id. col. 7 ll. 20–23. 

On April 20, 2015, Appellants, Eric Lemoine and TTC 

Performance Products, Inc. d/b/a Black Aces Tactical (collectively Lemoine), filed suit in the District of Connecticut 

alleging that Appellees, Mossberg Corporation and OF 

Mossberg & Sons, Inc.’s (collectively Mossberg), infringe 

the ’846 Patent based on its alleged making, offering for 

sale, and selling of its Model 590M box-style removable 

magazine shotgun. J.A. 25. On June 16, 2020, the district 

court issued a claim construction order determining that

(1) the preamble of claim 1 of the ’846 Patent is limiting, 

(2) “conventional shotgun” means “a traditional shotgun 

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LEMOINE v. MOSSBERG CORPORATION 3

that does not accept a removeable box magazine,” and (3) 

“for converting a conventional shotgun” means “for retrofitting a conventional shotgun after original manufacture.” 

J.A. 7–20. Because it is undisputed that Mossberg incorporates the box-style magazine of the Model 590M during

the original manufacture, the parties stipulated to a judgment of noninfringement of all claims of the ’846 Patent. 

J.A. 2–5. On July 20, 2020, the district court entered its

final judgment, adopting the parties’ stipulation. J.A. 1.

Lemoine appeals, arguing that the district court erred 

in its claim construction order. We have jurisdiction 

pursuant to 28 U.S.C. § 1295(a)(1). 

STANDARD OF REVIEW

Claim construction is an issue of law that we review de 

novo. Teva Pharm. USA, Inc. v. Sandoz, Inc., 574 U.S. 318, 

325–26 (2015). We review the district court's underlying 

factual findings for clear error. Id. at 322. “[W]hen the 

district court reviews only evidence intrinsic to the patent 

(the patent claims and specification, along with the patent’s prosecution history), the judge’s determination will 

amount solely to a determination of law,” which we review 

de novo. Id. at 331.

DISCUSSION

Lemoine contends that the district court erred by “inappropriately impos[ing] limitations on the ’846 Patent at 

claim construction, rendering the ’846 toothless against 

manufacturers who simply ‘convert’ existing models at the 

manufacturing stage” as opposed to “after original manufacture.” Appellant’s Br. 3–4. More specifically, Lemoine 

argues that the district court erred in construing the preamble phrase “for converting a conventional shotgun” to 

mean “for retrofitting a shotgun after original manufacture.” Id. at 4, 23. Lemoine also requests that the case be 

remanded with a requirement that “for converting a conventional shotgun” be construed to mean “regardless of 

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4 LEMOINE v. MOSSBERG CORPORATION

whether the modification is made by a manufacturer in its 

factory or by an owner of an existing conventional shotgun.” Id. 

Mossberg responds that the district court’s construction of the preamble phrase “for converting a conventional 

shotgun” represents the ordinary meaning of that phrase 

in view the intrinsic and extrinsic evidence and should be 

affirmed. Appellees’ Br. 12. Mossberg also contends that 

Lemoine waived its right to challenge the district court’s 

determination that the preamble of claim 1 is limiting by 

failing to meaningfully raise that issue before the district 

court or in its opening brief on appeal. Id. at 11–12.

First, as to whether claim 1 of the ’846 Patent is limiting, we agree with the district court and Mossberg that it 

is not entirely clear that Lemoine ever actually pulled the 

trigger in arguing that the preamble is not limiting. See, 

e.g., J.A. 7 n.5. Nonetheless, we determine that it is. 

The purpose of claim construction is to “determin[e] the 

meaning and scope of the patent claims asserted to be infringed.” Markman v. Westview Instruments, Inc., 52 F.3d 

967, 976 (Fed. Cir. 1995) (en banc), aff’d 517 U.S. 370, 

(1996). If a preamble is limiting, it becomes part of the 

claim. Eaton Corp. v. Rockwell Int'l Corp., 323 F.3d 1332, 

1339 (Fed. Cir. 2003). Whether a preamble is limiting is 

“determined on the facts of each case in light of the overall 

form of the claim, and the invention as described in the 

specification and illuminated in the prosecution history.” 

Applied Materials, Inc. v. Advanced Semiconductor Materials Am., Inc., 98 F.3d 1563, 1572–73 (Fed. Cir. 1996). 

Generally, the preamble does not limit the claims. 

Georgetown Rail Equip. Co. v. Holland L.P., 867 F.3d 1229, 

1236 (Fed. Cir. 2017). However, a preamble may be limiting if it recites essential structure or steps, or if it is necessary to give life, meaning, and vitality to the claim. Pitney 

Bowes, Inc. v. Hewlett–Packard Co., 182 F.3d 1298, 1305 

(Fed. Cir. 1999). 

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LEMOINE v. MOSSBERG CORPORATION 5

Here, the district court correctly held that the preamble of claim 1 of the ’846 Patent is limiting because it provides important context for the nature and structure of the 

invention being claimed, and that without the context provided by the preamble it is difficult to make sense of the 

claims. J.A. 12–16. For example, the preamble introduces 

the terms “shotgun magazine receiver assembly” and “conventional shotgun” and details the relationship between 

those terms, namely that the claimed invention is a “shotgun magazine receiver assembly” for “converting a conventional shotgun.” Without this context, it is difficult to make 

sense of the later disclosure of “mating,” “receiving,” or 

“communicating” the claimed invention to or with components of a “conventional shotgun.”. Further, as discussed 

in more detail below, the specification repeatedly discloses 

that the claimed invention is a retrofit kit for existing conventional shotguns. See ’846 Patent col. 1 ll. 1–3; see also 

id. col. 1 ll. 46–47. If the preamble was not limiting, these 

disclosures would be rendered meaningless. 

Having determined that the preamble of claim 1 of the 

’846 Patent is limiting, we next set our sights on the proper

construction of the preamble phrase “for converting a conventional shotgun.” We determine that the district court 

correctly construed this phrase to mean “for retrofitting a 

conventional shotgun after original manufacture.”

A claim should be construed in a manner that is consistent with the patent's specification. Markman, 52 F.3d

at 979 (“Claims must be read in view of the specification, of 

which they are a part.”). Typically, the specification is the 

best guide for construing the claims. See, e.g., Vitronics 

Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 

1996) (“[T]he specification is always highly relevant to the 

claim construction analysis. Usually, it is dispositive; it is 

the single best guide to the meaning of a disputed term.”).

When the specification describes the features of the 

“present invention” as a whole, this description limits the 

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6 LEMOINE v. MOSSBERG CORPORATION

scope of the invention. Honeywell Int’l, Inc. v. ITT Indus., 

452 F.3d 1312, 1318–19 (Fed. Cir. 2006). Here, the specification quite clearly characterizes the present invention as 

a “retrofit” conversion kit for use with an “existing” conventional shotgun. ’846 Patent col. 1 ll. 1–3 (“The present invention relates generally to shotguns and, more 

particularly to a retrofit magazine receiver for use with a 

conventional shotgun.”) (emphasis added); see also id. col. 

1 ll. 46–47 (“[T]he present invention is designed to be incorporated into existing shotguns.”) (emphasis added). 

The specification also discloses that the invention allows a “shotgun owner,” not a manufacturer, to “upgrade”

the receiver assembly of an existing conventional shotgun. 

See id. col. 1 ll. 35–41 (“[M]any shotgun owners often 

choose to upgrade their existing weapons with new stocks 

and barrels as opposed to purchasing a new weapon. Accordingly, it would be beneficial to provide a shotgun magazine receiver assembly which can replace the stock 

receiver of an existing shotgun to allow a user to rapidly 

fire and reload ammunition via a removable ‘box’ style 

magazine.”). 

Lemoine argues that these disclosures are merely exemplary and should not be read as limiting. In support, 

Lemoine points to common broadening language in the 

specification which states, for example, that: 

detailed embodiments of the present invention are 

disclosed herein; however, it is to be understood 

that the disclosed embodiments are merely exemplary of the invention which can be embodied in 

various forms.

Id. col. 2 ll. 44–47. But as the district court correctly 

noted, the specification makes clear that this language is 

meant to ensure that the invention is broad enough to be 

used with different types and models of shotguns, not in 

different phases of production. See, e.g., id. col. 2 l. 64–col. 

3 l. 9 (“As described herein, the term ‘shotgun’ can refer to 

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LEMOINE v. MOSSBERG CORPORATION 7

virtually any type and manufacturer of semi-automatic 

and/or shotguns. . . . Although illustrated in use with a 

MOSSBERG 500 shotgun, it is to be distinctly understood 

that the present invention has broader applications, and is 

equally applicable for use on many other shotguns without 

undue experimentation and without departing from the invention claimed.”). Moreover, neither the specification nor 

the claims include a single reference to the use of the 

claimed invention to manufacture a newly designed, or redesigned, shotgun with a box-style magazine. 

In light of these disclosures, we determine that the district court correctly held that a person of ordinary skill in

the art, having read the claims in light of the specification

and intrinsic record, would understand that within the 

meaning of the claims, “for converting a conventional shotgun” means “for retrofitting a conventional shotgun after 

original manufacture.”

CONCLUSION

We conclude that the district court’s determination 

that the preamble of claim 1 of the ’846 Patent is limiting

was on target, and that it correctly construed the preamble 

phrase “for converting a conventional shotgun,” to mean

“for retrofitting a conventional shotgun after original manufacture.” Accordingly, we affirm.

AFFIRMED

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